The inventive subject matter relates to a memory devices and methods of fabricating the same and, more particularly, to non-volatile memory devices and methods of fabricating the same.
Memory devices are used in a wide variety of apparatus, such as microcontrollers, credit cards, and the like. Memory devices can be classified into volatile memory devices, e.g., dynamic random access memory (DRAM) and static random access memory (SRAM) devices, in which data input/output can be performed quickly but data is lost as time elapses, and nonvolatile memory devices, e.g., read-only memory (ROM) devices, in which data input/output is performed relatively slowly but data can be permanently stored. Recently, there have been developed nonvolatile electrically-erasable programmable ROM (EEPROM) devices in which data input/output can be performed electrically. Such devices include flash memory devices and the like.
Such an EEPROM or flash memory device commonly has a memory cell structure in which a tunneling layer, a floating gate, an inter-gate dielectric layer structure, and a control gate electrode are sequentially formed on a semiconductor substrate. The floating gate is designed such that a coupling voltage is applied from the control gate electrode to the floating gate to establish an electric potential difference between the floating gate and the semiconductor substrate, and electrons are injected from the semiconductor substrate to the floating gate.
With the ongoing trend of device miniaturization, distances between lines forming such devices have decreased becomes small. The reduction in spacing between lines may increases coupling between the lines.